Nail clippers

ABSTRACT

The nail clipper contains a pair of blade bodies each having a cutting edge, a lever to be operated for bringing the cutting edges of the blade bodies into press contact with each other and a supporting shaft for linking the lever to the blade bodies; the cutting edges of the blade bodies being brought into press contact with each other by pressing the blade bodies with the lever against resilience of the blade bodies. The nail clipper is provided with bosses formed either on the lever or on the supporting shaft, so as to allow the supporting shaft to pivotally support the lever; and grooves formed on the rest of the supporting shaft and the lever, with which the bosses are engaged. Each groove has a mouth portion through which the boss is engaged and disengaged, a guiding portion capable of pivotally supporting the boss, and a connecting portion connecting the mouth portion and the guiding portion to each other. The groove has a pair of side wall surfaces opposing each other in the mouth portion, connecting portion and guiding portion and also a bottom surface connecting the side wall surfaces to each other.

TECHNICAL FIELD

[0001] The present invention relates to nail clippers.

BACKGROUND ART

[0002] A conventional nail clipper, for example, as shown in JapaneseUnexamined Utility Model Publication No. Sho 61-82502 has a supportingshaft which is notched to form a bearing hole, and a connecting pinattached to a lever is inserted to the bearing hole. In this nailclipper, although the lever can be incorporated into the supportingshaft easily by virtue of the bearing hole opening to the periphery ofthe shaft, this configuration per se involves problems that theconnecting pin of the lever easily slips off the bearing hole of thesupporting shaft and that the strength of the portion of the supportingshaft around the bearing hole is lowered. In addition, it is troublesometo form a supporting shaft having such a shape of bearing hole asdescribed above.

[0003] It is an objective of the present invention to provide nailclippers, capable of facilitating incorporation of a lever, ensuringbearing of the lever and enhancing the strength of the supportingsection. It is another objective of the present invention to provide anail clipper whose supporting shaft can be molded easily.

DISCLOSURE OF THE INVENTION

[0004] In order to attain the objectives as described above, the nailclipper according to one aspect of the present invention contains a pairof blade bodies each having a cutting edge, a lever to be operated forbringing the cutting edges of the blade bodies into press contact witheach other and a supporting shaft for linking the lever to the bladebodies. The cutting edges of the blade bodies are adapted to be broughtinto press contact with each other by pressing the blade bodies with thelever against resilience of the blade bodies. The nail clipper isprovided with a boss formed either on the lever or on the supportingshaft so as to allow the supporting shaft to pivotally support thelever, and a groove formed on the rest of the supporting shaft and thelever, with which the boss is engaged. The groove has a mouth portionthrough which the boss is engaged and disengaged, a guiding portioncapable of pivotally supporting the boss, and a connecting portionconnecting the mouth portion and the guiding portion to each other.Further, the groove has a pair of side wall surfaces opposing each otherin the mouth portion, connecting portion and guiding portion and also abottom surface connecting the side wall surfaces to each other.

[0005] The nail clipper according to another embodiment contains anupper blade body having an upper cutting edge; a lower blade body havinga lower cutting edge opposed to the upper cutting edge; a supportingshaft inserted to the blade bodies near the cutting edges respectively,a lower end portion of the supporting shaft being engaged with the lowerblade body to be locked therewith, while an upper end portion of thesupporting shaft protrudes upward through the upper blade body; and alever having a first supporting section; the first supporting sectionbeing linked on the upper blade body to a second supporting sectionprovided at an upper end portion of the supporting shaft; wherein thecutting edges of the blade bodies are brought into press contact witheach other by pressing the upper blade body with the lever againstresilience of the upper and lower blade bodies. In this nail clipper,either the first supporting section of the lever or the secondsupporting section of the supporting shaft is a boss, while the othersupporting section is a groove, with which the boss is engaged. Thegroove contains a mouth portion through which the boss is engaged anddisengaged, a guiding portion capable of pivotally supporting the boss,and a connecting portion connecting the mouth portion and the guidingportion to each other. The groove has a pair of side wall surfacesopposing each other in the mouth portion, connecting portion and guidingportion and also a bottom surface connecting the side wall surfaces toeach other.

[0006] The nail clipper according another embodiment contains an upperblade body having an upper cutting edge; a lower blade body having alower cutting edge opposed to the upper cutting edge; a supporting shaftinserted to the blade bodies near the cutting edges respectively, alower end portion of the supporting shaft being engaged with the lowerblade body, while an upper end portion of the supporting shaft protrudesupward through the upper blade body; a lever having a pair of supportingarms; the upper end portion of the supporting shaft being inserted onthe upper blade body to a bearing recess defined between the supportingarms of the lever; a first supporting section provided in the supportingarms; and a second supporting section provided at the upper end portionof the supporting shaft; the first and second supporting sections beinglinked to each other; wherein the upper cutting edge and the lowercutting edge are brought into press contact with each other by pressingthe upper blade body with the lever against resilience of the upper andlower blade bodies. In this nail clipper, either the first supportingsection of the lever or the second supporting section of the supportingshaft is a pair of bosses opposing each other, and the other supportingsection is a pair of grooves, with which the bosses are engagedrespectively. Each groove has a mouth portion through which the boss isengaged and disengaged, a guiding portion capable of pivotallysupporting the boss, and a connecting portion connecting the mouthportion and the guiding portion to each other. Each groove has a pair ofside wall surfaces opposing each other in the mouth portion, connectingportion and guiding portion and also a bottom surface connecting theside wall surfaces to each other.

[0007] The nail clipper according to another embodiment contains anupper blade body having an upper cutting edge; a lower blade body havinga lower cutting edge opposed to the upper cutting edge; a supportingshaft inserted to the blade bodies near the cutting edges respectively,a lower end portion of the supporting shaft being engaged with the lowerblade body to be locked therewith, while an upper end portion of thesupporting shaft protrudes upward through the upper blade body; and alever having a pair of supporting arms; the upper end portion of thesupporting shaft being inserted on the upper blade body to a bearingrecess defined between the supporting arms of the lever; a firstsupporting section provided in the supporting arms; and a secondsupporting section provided at the upper end portion of the supportingshaft; the first and second supporting sections being linked to eachother; wherein the upper cutting edge and the lower cutting edge arebrought into press contact with each other by pressing the upper bladebody with the lever against resilience of the upper and lower bladebodies. In this nail clipper, the first supporting section of the leveris a pair of bosses protruding from the supporting arms respectively tooppose each other in the bearing recess of the lever; whereas the secondsupporting section of the supporting shaft is a groove formedcontinuously fully along the circumference thereof, with which thebosses are engaged. Each groove has a mouth portion through which thebosses are engaged and disengaged and a guiding portion capable ofpivotally supporting the bosses.

[0008] The nail clipper according to another embodiment contains anupper blade body having an upper cutting edge; a lower blade body havinga lower cutting edge opposed to the upper cutting edge; a supportingshaft inserted to the blade bodies near the cutting edges respectively,a lower end portion of the supporting shaft being engaged with the lowerblade body to be locked therewith, while an upper end portion of thesupporting shaft protrudes upward through the upper blade body; a firstsupporting section provided in a lever; and a second supporting sectionprovided at the upper end portion of the supporting shaft, the first andsecond supporting sections being linked to each other; wherein the uppercutting edge and the lower cutting edge are brought into press contactwith each other by pressing the upper blade body with the lever againstresilience of the upper and lower blade bodies. In this nail clipper,the supporting shaft is molded with a synthetic resin material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1(a) is a front view of the nail clipper according to a firstembodiment, showing a state where the nail clipper is at rest; FIG. 1(b)is a perspective view showing the supporting shaft of the nail clipper;and FIG. 1(c) is a perspective view showing the lever of the nailclipper;

[0010]FIG. 2(a) is a front view of the supporting shaft of the nailclipper; FIG. 2(b) is a left side view of the supporting shaft shown inFIG. 2(a); and FIG. 2(c) is a bottom view of the supporting shaft shownin FIG. 2(a);

[0011]FIG. 3(a) is a cross-sectional view taken along the line 3 a-3 ain FIG. 2(a); FIG. 3(b) is a cross-sectional view taken along the line 3b-3 b in FIG. 2(a); and FIG. 3(c) is a cross-sectional view taken alongthe line 3 c-3 c in FIG. 2(a);

[0012]FIG. 4(a) is a partial plan view of the lever of the nail clipper;and FIG. 4(b) is a left side view of the lever shown in FIG. 4(a);

[0013] FIGS. 5(a), 5(b) and 5(c) are partial cross-sectional viewsshowing process steps of engaging the pair of bosses of the lever withthe grooves of the supporting shaft;

[0014]FIG. 6(a) is a cross-sectional view taken along the line 6 a-6 ain FIG. 5(b); and FIG. 6(b) is a cross-sectional view taken along theline 6 b-6 b in FIG. 5(c);

[0015]FIG. 7(a) is a front view of the nail clipper according to thefirst embodiment showing a state where the nail clipper is ready foruse; and FIG. 7(b) is a front view thereof showing a state where thenail clipper is in action;

[0016]FIG. 8(a) is a front view showing the support shaft in the nailclipper according to another embodiment; FIG. 8(b) is a left side viewof the supporting shaft shown in FIG. 8(a); FIG. 8(c) is across-sectional view taken along the liner 8c-8c in FIG. 8(a); and FIG.8(d) is a cross-sectional view taken along the line 8 d-8 d in FIG.8(a);

[0017]FIG. 9(a) is a cross-sectional view showing a transient step offorming bosses in the lever of the nail clipper according to anotherembodiment; and FIG. 9(b) is a cross-sectional view showing the bosses;and

[0018]FIG. 10(a) is a front view showing the groove of the supportingshaft in the nail clipper according to another embodiment; and FIG.10(b) is a cross-sectional view taken along the line 10 b-10 b in FIG.10(a).

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] The nail clipper according to a first embodiment of the presentinvention will be described below referring to FIGS. 1 to 7.

[0020] Scheme of Nail Clipper

[0021] As shown in FIG. 1(a), the nail clipper has an upper blade body 1and a lower blade body 2 each having a plate form, which are fixed toeach other at proximal portions 1 a and 2 a. The upper blade body 1 andthe lower blade body 2 have resilience and can be moved closer to andaway from each other. The upper blade body 1 and the lower blade body 2have cutting edges 3 and 4 formed at the distal ends thereofrespectively to oppose each other. The upper cutting edge 3 and thelower cutting edge 4 are normally spaced away from each other by theresilience of the blade bodies 1 and 2. As shown in FIGS. 5(a), 5(b) and5(c), circular bearing holes 5 and 6 are defined through the upper bladebody 1 and the lower blade body 2, and they are located near the cuttingedges 3 and 4, respectively.

[0022] A supporting shaft 7 shown in FIG. 1(b) penetrates the upperblade body 1 through the bearing hole 5 thereof and the lower blade body2 through the bearing hole 6 thereof. This supporting shaft 7 contains alarge-diameter head 8 formed at the lower end thereof and asmall-diameter shank 10 extended from the head 8 upward through a step9. The head 8 is locked by the rim of the bearing hole 6 on the lowerside of the lower blade body 2. An upper end portion 11 of the shank 10protrudes through the bearing hole 5 to the upper side of the upperblade body 1.

[0023] A lever 12 shown in FIG. 1(c) is placed on the upper side of theupper blade body 1. The lever 12 is forked at the distal portion to forma pair of supporting arms 13 and also a bearing recess 14 between thesetwo supporting arms 13. The upper end portion 11 of the supporting shaft7 is inserted to this bearing recess 14. Each supporting arm 13 of thelever 12 and the upper end portion 11 of the supporting shaft 7 arelinked to each other in a supporting section S.

[0024] Materials of Supporting Shaft 7 and Lever 12

[0025] Both the supporting shaft 7 and the lever 12 are integrallymolded respectively with a synthetic resin material. The synthetic resinmaterial is based on polyamide, polypropylene or aromatic nylon and cancontain a predetermined filler. As the filler, a glass fiber, a mineralfiber or a carbon fiber can be used singly, or a combination of at leasttwo of the glass fiber, mineral fiber and carbon fiber may be used.Provided that the content (wt %) of such fillers is α, the value α isdefined in this embodiment as 15%≦α≦65%. However, it is preferably40%≦α≦60%.

[0026] The following characteristics can be obtained by utilizing suchsynthetic resins.

[0027] (1) Synthetic resins have high strength and high rigidity afterwetting or at high temperatures, high impact strength and highelongation at break as rigid materials and excellent fatigue strength,so that the shaft 7 and the lever 12 come to have high strength andrigidity.

[0028] (2) Synthetic resins have good fluidity and provide goodappearance, since they can be subjected to injection molding at a moldtemperature of 80 to 110° C. and since dies, screws and cylinders do notwear much; and

[0029] (3) Synthetic resins do not wear much when they are brought intocontact with metallic materials to improve wear resistance of the shaft7 and of the lever 12.

[0030] Linking Structure of Supporting Shaft 7 and Lever 12

[0031] As shown in FIG. 1(c), in the bearing recess 14 of the lever 12,a boss 15 (supporting section S) is formed on each supporting arm 13such that the boss formed on one supporting arm 13 opposes thecounterpart formed on the other supporting arm 13. Both the head 8 andthe shank 10 of the supporting shaft 7 are formed to have circular crosssections respectively. The shank 10 has on each side of thecircumference thereof a pair of grooves 16 (supporting section S) at180° intervals to oppose the bosses 15 respectively, and the bosses 15are engaged with the opposing grooves 16 respectively.

[0032] As shown in FIGS. 1(b), 2(a) to 2(c) and FIGS. 3(a) to 3(c), eachgroove 16 contains a mouth portion 17 engageable with and disengageablefrom the boss 15, a guiding portion 18 capable of pivotally supportingthe boss 15, and a connecting portion 19 connecting the mouth portion 17and the guiding portion 18 to each other. Each groove 16 has a pair ofopposing side wall surfaces 20 in the mouth portion 17, connectingportion 19 and guiding portion 18; a bottom surface 21 connecting thepair of side wall surfaces 20 to each other in the mouth portion 17,connecting portion 19 and guiding portion 18; and an opening 22 opposingthe bottom surface 21. The pair of grooves 16 are separated from eachother by a common bottom plate 23 throughout the mouth portion 17,connecting portion 19 and guiding portion 18. The bottom surfaces 21 ofthe grooves 16 are located on each side of the bottom plate 23 in themouth portion 17, connecting portion 19 and guiding portion 18.

[0033] The center line between the pair of side wall surfaces 20 in eachgroove 16 extends throughout the mouth portion 17, connecting portion 19and guiding portion 18. The center line contains a first portion 17 arunning through the mouth portion 17, a second portion 19 a runningthrough the connecting portion 19 and a third portion 18 a runningthrough the guiding portion 18. The first portion 17 a extends from themouth portion 17 to the connecting portion 19 orthogonally to the axialdirection 7 a of the supporting shaft 7. The third portion 18 a extendsfrom the connecting portion 19 to the guiding portion 18 along the axialdirection 7 a of the supporting shaft 7. The second portion 19 a isarcuated to connect the first portion 17 a and the third portion 18 a toeach other.

[0034] The pair of side wall surfaces 20 in each groove 16 are inclinedto be away from each other toward the opening 22. Thus, the distance Wbetween the side wall surfaces 20 in each groove 16 is designed to begreater on the opening (22) side than on the bottom surface (21) side.

[0035] Provided that the thickness of the bottom plate 23 or thedistance between the bottom surfaces 21 of the grooves 16 is T; thedistance between the opening 22 of the grooves 16 or the outsidediameter of the shank 10 of the supporting shaft 7 is D₁₀; and that thevalue T (thickness)/D₁₀ (outside diameter) is A, the value A is setwithin the range of 0≦A≦0.5. More preferably, the value A is set withinthe range of 0.2≦A≦0.4. In each groove 16 of this embodiment, the bottomplate 23 is formed throughout the mouth portion 17, connecting portion19 and guiding portion 18. However, for example, the bottom plate 23 maybe formed in the mouth portion 17 and a part of the connecting portion19, and the bottom plate 23 may be omitted in the rest of the connectingportion 19 and in the guiding portion 18 to allow the grooves 16 tocommunicate with each other. In the case where the bottom plate 23 isomitted, T=0, and hence A=0.

[0036] Provided that the distance between the side wall surfaces 20 inthe guiding portion 18 of each groove 16 and the outside diameter of theshank 10 of the supporting shaft 7 are W and D₁₀ respectively and thatthe value W (distance)/D₁₀ (outside diameter) is B, the value B is setwithin the range of 0.15≦B≦0.8 in this embodiment. The value B is morepreferably set within the range of 0.4≦B≦0.7.

[0037] In the supporting shaft 7, the outside diameter D₈ of the head 8is designed to be greater than the outside diameter D₁₀ of the shank 10.Provided that the length of the head 8 along the axial direction 7 a andthe length of the shank 10 along the axial direction 7 a are H and Lrespectively and that the value H (width)/L (length) is C, the value Cis set within the range of 0.05≦C≦0.3 in this embodiment. The value C ismore preferably set within the range of 0.1≦C≦0.2.

[0038] Further, in the supporting shaft 7, the step 9 present betweenthe head 8 and the shank 10 has a reinforcing portion 24 having anarcuate cross section formed fully along the outer circumference.Provided that the radius of the reinforcing portion 24 is r, the value ris set within the range of 0.1 mm≦r≦3 mm. The value r is more preferablyset within the range of 0.2 mm≦r≦1.5 mm.

[0039] Referring to the thickness T of the bottom plate 23 presentbetween the grooves 16, each bottom surface 21 is sloped or stepped fromthe mouth portion 17 toward the guiding portion 18 so that the thicknessT is greater on the mouth portion (17) side than on the guiding portion(18) side. In other words, each groove 16 is designed to have such adepth as is slightly shallower on the mouth portion (17) side than onthe guiding portion (18) side. Meanwhile, the distance W between theside wall surfaces 20 in each groove 16 is designed to be greater on themouth portion (17) side than on the connecting portion (19) side or thepivotal guiding portion (18) side. Further, the supporting shaft 7 has alocking pin hole 25 formed in the head 8 thereof.

[0040] Next, the bosses 15 shown in FIG. 1(c) and FIGS. 4(a) and 4(b)will be described. Each boss 15 has a peripheral surface 28 formed toextend from a proximal portion 26 to a distal portion 27 thereof, and anend face 29 provided at the distal portion 27. In each boss 15, thecross section taken orthogonal to the axial direction 15 a has acircular shape. The peripheral surface 28 is tilted with respect to theaxial direction 15 a. The peripheral surface 28 of each boss 15 isdesigned to have an outside diameter D₂₆ at the proximal portion 26,which is greater than the outside diameter D₂₇ Of the same at the distalportion 27. Thus, a cross-sectional area of each boss 15 takenorthogonal to the axial direction 15 a reduces gradually from theproximal portion (26) side toward the distal portion (27) side.

[0041] In each boss 15, provided that the outside diameter of theperipheral surface 28 at the proximal portion 26 and the length from theproximal portion 26 to the distal portion 27 in the axial direction 15 aare D₂₆ and M respectively, and that the value D₂₆ (outside diameter)/M(length) is E, the value E is set within the range of 1≦E≦3 in thisembodiment. The value E is more preferably set within the range of1.5≦E≦2.5.

[0042] In the bosses 15, provided that the sum of the length M in theaxial direction 15 a from the proximal portion 26 to the distal portion27 in one boss 15 and the length M in the axial direction 15 a from theproximal portion 26 to the distal portion 27 in the other boss 15 is N(M+M), and the dimension of a clearance 30 secured between the distalportions 27 of the bosses 15 (i.e., the clearance between the end faces29) is P, and that the value N (sum of lengths)/P (clearance) is F, thevalue F is set within the range of 1≦F≦3 in this embodiment. The value Fis more preferably set within the range of 1.3≦F≦2.3.

[0043] Next, the procedures of coupling the bosses 15 with the grooves16 respectively and supporting state between them will be described.

[0044] As shown in FIG. 5(a), in the state where the supporting shaft 7penetrates through the upper and lower blade bodies 1 and 2, a lockingpin (not shown) is inserted to the locking pin hole 25 formed at thehead 8 of the supporting shaft 7 to achieve positioning of thesupporting shaft 7, and also the upper blade body 1 is pushed down sothat the cutting edges 3 and 4 of the blade bodies 1 and 2 approach eachother. In this state, the supporting arms 13 of the lever 12 are appliedonto the upper side of the upper blade body 1, and the bosses 15 of thesupporting arms 13 are moved, on the upper side of the upper blade body1, toward the grooves 16 formed at the upper end portion 11 of the shank10 in the supporting shaft 7.

[0045] Next, as shown in FIGS. 5(b) and 6(a), each boss 15 is engagedwith the mouth portion 17 of the opposed groove 16 while the upper endportion 11 of the shank 10 is inserted to the bearing recess 14 definedbetween the supporting arms 13. At the initial stage of engagement, eachboss 15 approaches the side wall surfaces 20 of the groove 16 such thatthe peripheral surface 28 of the boss 15 slides along the side wallsurfaces 20 of the groove 16 and that the end face 29 of the boss 15slides along the bottom surface 21 of the groove 16.

[0046] Further, as shown in FIGS. 5(c) and 6(b), each boss 15 is slippedfrom the mouth portion 17 of the groove 16 into the guiding portion 18through the connecting portion 19 in each groove. In the state where theboss 15 is fully engaged with the groove 16, the boss 15 is brought intopressure contact with the side wall surfaces 20 of the guiding portion18 under the resilience of the upper and lower blade bodies 1 and 2 soas to regulate the boss 15 not to shift toward the connecting portion 19of the groove 16.

[0047] Example of How the Nail Clipper is Used

[0048] In the state where the nail clipper is at rest as shown in FIG.1(a), the lever 12 is turned over to rest on the upper side of the upperblade body 1, and the upper and lower blade bodies 1 and 2 are spacedvertically from each other under the resilience thereof. In this state,the resilience of the upper blade body 1 is borne by the bosses 15 andthe grooves 16 formed in the shank 10 of the supporting shaft 7 throughthe supporting arms 13 of the lever 12; whereas the resilience of thelower blade body 2 is borne by the head 8 of the supporting shaft 7,maintaining the upper cutting edge 3 and the lower cutting edge 4 to bespaced away from each other.

[0049] Next, the lever 12 is pivoted on the upper side of the upperblade body 1 by 180° together with the supporting shaft 7 and theninverted to be positioned over the upper blade body 1 so as to form anupward slope with respect to the blade body 1, as shown in FIG. 7(a)illustrating the state where the nail clipper is ready for use. Then,the upper blade body 1 is pressed with the lever 12 against theresilience of the upper and lower blade bodies 1 and 2, and the uppercutting edge 3 and the lower cutting edge 4 are brought closer andabutted against each other, as shown in FIG. 7(b) illustrating the statewhere the nail clipper is in action.

[0050] In any of the states described above, the bosses 15 of the lever12 move within the guiding portions 18 of the respective grooves 16defined in the supporting shaft 7 following the movement of the lever12.

[0051] Other Embodiments

[0052] Another Embodiment Shown in FIG. 8

[0053] In the first embodiment shown in FIGS. 2(a) and 2(b), each groove16 has the mouth portion 17 only on one side of the axial line 7 a ofthe supporting shaft 7. However, in the embodiment shown in FIGS. 8(a)and 8(b), each groove 16 has a pair of mouth portions 17 on each side ofthe axial line 7 a of the supporting shaft 7.

[0054] Another Embodiment Shown in FIG. 9

[0055] In the first embodiment shown in FIG. 1(c), the entire lever 12including the bosses 15 is molded with a synthetic resin material.However, in the embodiment shown in FIG. 9(a), the main body of thelever 12 is molded with a synthetic resin material, and a metallicboss-forming material 31 is inserted to the supporting arms 13 to beintegrated with the lever 12, and then the boss-forming material 31 iscut to form a pair of bosses 15.

[0056] Another Embodiment Shown in FIG. 10

[0057] In the first embodiment, the grooves 16 are defined on theperiphery of the shank 10 of the supporting shaft 7 to opposediametrically each other. In place of this constitution, a groove 16 isformed fully along the circumference of the shank 10 of the supportingshaft 7. This groove 16 has an upper edge and a lower edge, and theupper edge has a wavy convexoconcavity 32. Further, a guiding portion 18also serving as a mouth portion 17 is provided between each concavity32a of the upper edge and the lower edge. The boss 15 in each supportingarm 13 of the lever 12 is introduced through this mouth portion 17 intothe guiding portion 18.

[0058] Although not illustrated, the groove formed fully along thecircumference of the shank 10 of the supporting shaft 7 may have thefollowing constitution. A crosswise groove is formed on the shank 10 ofthe supporting shaft 7 in the circumferential direction. While thecrosswise groove has an upper edge and a lower edge intersecting withthe axial direction 7 a, a plurality of vertical grooves are formed toextend parallelwise from the upper edge in the axial direction. Thecrosswise groove serves both as a mouth portion and as a connectingportion. Each vertical groove serves both as a connecting portion and asa guiding portion. The bosses 15 in the supporting arms 13 of the lever12 are introduced from the mouth portion into the guiding portionsthrough the connecting portions, respectively.

[0059] In any of the above embodiments, the supporting shaft 7 isprovided with a groove or grooves 16, whereas each supporting arm 13 ofthe lever 12 is provided with a boss 15. Although not illustrated, inplace of this configuration, a boss may be formed on the supportingshaft 7, and a groove may be formed on each supporting arm 13 of thelever 12.

[0060] Although not shown, the configuration of the boss 15 in eachsupporting arm 13 of the lever 12 may be modified. While the bosses 15in the foregoing embodiments have a truncated cone shape, they may have,for example, a columnar or semispherical shape. Further, each boss 15may have an elliptical cross section in place of the circular crosssection.

1. In a nail clipper containing a pair of blade bodies each having acutting edge, a lever to be operated for bringing the cutting edges ofthe blade bodies into press contact with each other and a supportingshaft for linking the lever to the blade bodies; the cutting edges ofthe blade bodies being brought into press contact with each other bypressing the blade bodies with the lever against resilience of the bladebodies, wherein the improvement which comprises: a boss formed either onthe lever or on the supporting shaft, so as to allow the supportingshaft to pivotally support the lever; and a groove formed on the rest ofthe supporting shaft and the lever, with which the boss is engaged; thegroove having a mouth portion through which the boss is engaged anddisengaged, a guiding portion capable of pivotally supporting the boss,and a connecting portion connecting the mouth portion and the guidingportion to each other; the groove having a pair of side wall surfacesopposing each other in the mouth portion, connecting portion and guidingportion and also a bottom surface connecting the side wall surfaces toeach other.
 2. In a nail clipper containing an upper blade body havingan upper cutting edge; a lower blade body having a lower cutting edgeopposed to the upper cutting edge; a supporting shaft inserted to theblade bodies near the cutting edges respectively, a lower end portion ofthe supporting shaft being engaged with the lower blade body to belocked therewith, while an upper end portion of the supporting shaftprotrudes upward through the upper blade body; and a lever having afirst supporting section; the first supporting section being linked onthe upper blade body to a second supporting section provided at an upperend portion of the supporting shaft; the cutting edges of the bladebodies being brought into press contact with each other by pressing theupper blade body with the lever against resilience of the upper andlower blade bodies, wherein the improvement which comprises: a bossformed as the first supporting section of the lever or as the secondsupporting section of the supporting shaft, and a groove formed as theother supporting section, with which the boss is engaged; the groovehaving a mouth portion through which the boss is engaged and disengaged,a guiding portion capable of pivotally supporting the boss, and aconnecting portion connecting the mouth portion and the guiding portionto each other; the groove having a pair of side wall surfaces opposingeach other in the mouth portion, connecting portion and guiding portionand also a bottom surface connecting the side wall surfaces to eachother.
 3. In a nail clipper containing an upper blade body having anupper cutting edge; a lower blade body having a lower cutting edgeopposed to the upper cutting edge; a supporting shaft inserted to theblade bodies near the cutting edges respectively, a lower end portion ofthe supporting shaft being engaged with the lower blade body, while anupper end portion of the supporting shaft protrudes upward through theupper blade body; a lever having a pair of supporting arms; the upperend portion of the supporting shaft being inserted on the upper bladebody to a bearing recess defined between the supporting arms of thelever; a first supporting section provided in the supporting arms; and asecond supporting section provided at the upper end portion of thesupporting shaft; the first and second supporting sections being linkedto each other; the upper cutting edge and the lower cutting edge beingbrought into press contact with each other by pressing the upper bladebody with the lever against resilience of the upper and lower bladebodies, wherein the improvement which comprises: a pair of bossesopposing each other, formed as the first supporting section of the leveror as the second supporting section of the supporting shaft, and a pairof grooves formed as the other supporting section, with which the bossesare engaged respectively; the grooves each having a mouth portionthrough which the boss is engaged and disengaged, a guiding portioncapable of pivotally supporting the boss, and a connecting portionconnecting the mouth portion and the guiding portion to each other; thegroove having a pair of side wall surfaces opposing each other in themouth portion, connecting portion and guiding portion and also a bottomsurface connecting the side wall surfaces to each other.
 4. The nailclipper according to claim 3, wherein the bosses formed as onesupporting section are provided in the supporting arms respectively tooppose each other in the bearing recess of the lever, whereas thegrooves formed as the other supporting section are defined on thecircumference of the supporting shaft to oppose the bosses respectively.5. The nail clipper according to claim 4, wherein the grooves defined inthe supporting shaft are separated from each other by a bottom platethroughout the mouth portion, connecting portion and guiding portion,and each groove has a bottom surface formed on the bottom platethroughout the mouth portion, connecting portion and guiding portion. 6.The nail clipper according to claim 5, wherein the distance between thebottom surfaces of the grooves or the thickness of the bottom plate isdesigned to be greater on the mouth portion side than on the guidingportion side.
 7. The nail clipper according to claim 5 or 6, whereinprovided that T represents the distance between the bottom surfaces ofthe grooves or the thickness of the bottom plate; D₁₀ represents theoutside diameter of the supporting shaft; and A represents a value T(thickness)/D₁₀(outside diameter), the value A is set within the rangeof 0≦A≦0.5.
 8. The nail clipper according to any of claims 4 to 7,wherein a central line between the side wall surfaces in each groove ofthe supporting shaft extends through the mouth portion, connectingportion and guiding portion and contains a first portion passing throughthe mouth portion, a second portion passing through the connectingportion and a third portion passing through the guiding portion.
 9. Thenail clipper according to claim 8, wherein the second portion of thecentral line contains a portion extending from the mouth portion to theconnecting portion orthogonal to the axial direction of the supportingshaft, and a portion extending from the connecting portion to theguiding portion in the axial direction of the supporting shaft.
 10. Thenail clipper according to claim 9, wherein provided that W representsthe distance between the side wall surfaces in the guiding portion ofeach groove; D₁₀ represents the outside diameter of the supportingshaft; and B represents a value W (distance)/D₁₀ (outside diameter), thevalue B is set within the range of 0.15≦B≦0.8.
 11. The nail clipperaccording to any of claims 4 to 10, wherein the distance W between theside wall surfaces of each groove is designed to be greater on the mouthportion side than on the connecting portion side or on the guidingportion side.
 12. The nail clipper according to claim 4, wherein eachboss has a proximal portion, a distal portion, a peripheral surface andan end face at the distal portion; the boss has a cross-sectional areaorthogonal to the axial direction thereof, which is designed to begreater on the proximal side than on the distal side.
 13. The nailclipper according to claim 12, wherein the cross section of each bossorthogonal to the axial direction thereof has a circular shape, and theoutside diameter of the boss reduces gradually from the proximal portiontoward the distal portion.
 14. The nail clipper according to claim 13,wherein provided that D₂₆ represents the outside diameter of theproximal portion of each boss; M represents the axial length of the bossfrom the proximal portion to the distal portion; and E represents avalue D₂₆ (outside diameter)/M (length), the value E is set within therange of 1≦E≦3.
 15. The nail clipper according to claim 13 or 14,wherein provided that N represents the sum of the lengths M in the pairof bosses; P represents the distance between the end faces of thebosses; and F represents a value N (sum of lengths)/P (distance), thevalue F is set within the range of 1≦F≦3.
 16. The nail clipper accordingto claim 4, wherein the both side wall surfaces in each groove of thesupporting shaft are provided adjacent to each other so that they aresubstantially in contact with the peripheral surface of the boss of thelever.
 17. The nail clipper according to claim 16, wherein the distanceW between the side wall surfaces in each groove of the supporting shaftis designed to be greater on the opening side than on the bottom surfaceside such that it becomes smaller toward the deeper side of the groove.18. The nail clipper according to any of claims 4 to 17, wherein thesupporting shaft has a head located at the lower end thereof and a shankformed contiguous to the head through a step; the head has an outsidediameter D₈ which is greater than the outside diameter D₁₀ of the shank;and provided that H represents the axial length of the head, Lrepresents the axial length of the shank and C represents a value H(width)/L (length), the value C is set within the range of 0.05≦C≦0.3.19. The nail clipper according to claim 18, wherein the step formedbetween the head and the shank in the supporting shaft is provided witha reinforcing portion having an arcuate cross section formed fully alongthe periphery thereof, and provided that r represents the radius in across sectional profile of the reinforcing portion, the value r is setwithin the range of 0.1 mm≦r≦3 mm.
 20. The nail clipper according to anyof claims 4 to 19, wherein, when the boss is supported in the guidingportion of the groove, the boss is brought into press contact with theside wall surfaces of the guiding portion under resilience of the upperand lower blade bodies so that it does not shift toward the connectingportion of the groove.
 21. The nail clipper according to claim 4,wherein each groove has a pair of mouth portions defined on each side ofthe axial line of the supporting shaft.
 22. The nail clipper accordingto any of claims 4 to 21, wherein the bosses on the supporting arms ofthe lever are made of a metal, and in the case where the lever is moldedwith a synthetic resin material, the bosses are formed integrally withthe lever using an insert.
 23. The nail clipper according to any ofclaims 4 to 22, wherein the supporting shaft has at the lower end alocking pin hole.
 24. In a nail clipper containing an upper blade bodyhaving an upper cutting edge; a lower blade body having a lower cuttingedge opposed to the upper cutting edge; a supporting shaft inserted tothe blade bodies near the cutting edges respectively, a lower endportion of the supporting shaft being engaged with the lower blade bodyto be locked therewith, while an upper end portion of the supportingshaft protrudes upward through the upper blade body; and a lever havinga pair of supporting arms; the upper end portion of the supporting shaftbeing inserted on the upper blade body to a bearing recess definedbetween the supporting arms of the lever; a first supporting sectionprovided in the supporting arms; and a second supporting sectionprovided at the upper end portion of the supporting shaft; the first andsecond supporting sections being linked to each other; the upper cuttingedge and the lower cutting edge being brought into press contact witheach other by pressing the upper blade body with the lever againstresilience of the upper and lower blade bodies, wherein the improvementwhich comprises: a pair of bosses protruding as the first supportingsection of the lever from the supporting arms respectively to opposeeach other in the bearing recess of the lever; and a groove, with whichthe bosses are engaged, formed as the second supporting section of thesupporting shaft on the circumference thereof; the groove being formedcontinuously fully along the circumference of the supporting shaft andhaving a mouth portion through which the bosses are engaged anddisengaged and a guiding portion capable of pivotally supporting thebosses.
 25. A nail clipper comprising an upper blade body having anupper cutting edge; a lower blade body having a lower cutting edgeopposed to the upper cutting edge; a supporting shaft inserted to theblade bodies near the cutting edges respectively, a lower end portion ofthe supporting shaft being engaged with the lower blade body to belocked therewith, while an upper end portion of the supporting shaftprotrudes upward through the upper blade body; a first supportingsection provided in a lever; and a second supporting section provided atthe upper end portion of the supporting shaft, the first and secondsupporting sections being linked to each other; the upper cutting edgeand the lower cutting edge being brought into press contact with eachother by pressing the upper blade body with the lever against resilienceof the upper and lower blade bodies; wherein the supporting shaft ismolded with a synthetic resin material.
 26. The nail clipper accordingto claim 25, wherein the supporting shaft comprises a head located atthe lower end thereof and a shank formed contiguous to the head througha step; the head has a diameter D₈ which is designed to be greater thanthe outside diameter D₁₀of the shank; and provided that H and Lrepresent the axial length of the head and the axial length of the shankrespectively and that C represents a value H (width)/L (length), thevalue C is set within the range of 0.05≦C≦0.3.
 27. The nail clipperaccording to claim 26, wherein the step formed between the head and theshank of the supporting shaft is provided with a reinforcing portionhaving an arcuate cross section, formed fully along the peripherythereof, and provided that r represents a radius in a cross section ofthe reinforcing portion, the value r is set within the range of 0.1mm≦r≦3 mm.
 28. The nail clipper according to any of claims 2 to 24,wherein the supporting shaft is molded with a synthetic resin material.29. The nail clipper according to any of claims 2 to 28, wherein thesynthetic resin material for molding the supporting shaft comprises amajor component selected from the group consisting of polyamide,polypropylene and aromatic nylon; and a filler to be added in an amountof 15% to 65% relative to the major component, the filler being at leastone kind of fiber selected from the group consisting of glass fiber,mineral fiber and carbon fiber.
 30. The nail clipper according to any ofclaims 1 to 29, wherein the lever is molded with a synthetic resinmaterial.
 31. The nail clipper according to claim 30, wherein thesynthetic resin material for molding the lever comprises a majorcomponent selected from the group consisting of polyamide, polypropyleneand aromatic nylon; and a filler to be added in an amount of 15% to 65%relative to the major component, the filler being at least one kind offiber selected from the group consisting of glass fiber, mineral fiberand carbon fiber.